The email now shows one link.
I was still getting a "Unknown column 'users.randomString' in 'where clause'" when I click the link and it goes to the user-confirm.php page.
Totally my fault!! You can see below I simply copied the text from the tutorial forgetting that MY users database is not called "users" but "entry". Below I use users.randomString <> '0' in the where clause rather than what it should be entry.randomString <> '0'
WHERE ID = colname AND entry.randomString = paramrandomString AND entry.EmailAddress = paramemail AND users.randomString <> '0'
"Double opt in" works great now.